| 1. |
- Andersson, Martin O., et al.
(författare)
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Molecular survey of neglected bacterial pathogens reveals an abundant diversity of species and genotypes in ticks collected from animal hosts across Romania
- 2018
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Ingår i: Parasites & Vectors. - : BioMed Central. - 1756-3305. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Ticks are transmitting a wide range of bacterial pathogens that cause substantial morbidity and mortality in domestic animals. The full pathogen burden transmitted by tick vectors is incompletely studied in many geographical areas, and extensive studies are required to fully understand the diversity and distribution of pathogens transmitted by ticks. Results: We sampled 824 ticks of 11 species collected in 19 counties in Romania. Ticks were collected mainly from dogs, but also from other domestic and wild animals, and were subjected to molecular screening for pathogens. Rickettsia spp. was the most commonly detected pathogen, occurring in 10.6% (87/824) of ticks. Several species were detected: Rickettsia helvetica, R. raoultii, R. massiliae, R. monacensis, R. slovaca and R. aeschlimannii. A single occurrence of the zoonotic bacterium Bartonella vinsonii berkhoffii was detected in a tick collected from a dog. Anaplasma phagocytophilum occurred in four samples, and sequences similar to Anaplasma marginale/ovis were abundant in ticks from ruminants. In addition, molecular screening showed that ticks from dogs were carrying an Ehrlichia species identical to the HF strain as well as the enigmatic zoonotic pathogen "Candidatus Neoehrlichia mikurensis". An organism similar to E. chaffeensis or E. muris was detected in an Ixodes ricinus collected from a fox. Conclusions: We describe an abundant diversity of bacterial tick-borne pathogens in ticks collected from animal hosts in Romania, both on the level of species and genotypes/strains within these species. Several findings were novel for Romania, including Bartonella vinsonii subsp. berkhoffii that causes bacteremia and endocarditis in dogs. "Candidatus Neoehrlichia mikurensis" was detected in a tick collected from a dog. Previously, a single case of infection in a dog was diagnosed in Germany. The results warrant further studies on the consequences of tick-borne pathogens in domestic animals in Romania.
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| 2. |
- Andersson, Martin O., et al.
(författare)
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New records and host associations of the tick Ixodes apronophorus and the first detection of Ehrlichia sp HF in Romania
- 2018
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Ingår i: Parasitology Research. - : Springer. - 0932-0113 .- 1432-1955. ; 117:4, s. 1285-1289
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Tidskriftsartikel (refereegranskat)abstract
- Ixodes (Ixodes) apronophorus is a neglected tick species and its geographical distribution, host associations, and role as a disease vector are not well known. We collected I. apronophorus from several locations in Romania. Morphological identification of ticks was confirmed by analysis of 16S rDNA and 12S rDNA gene sequences. We report new host associations of I. apronophorus, which was collected from dogs, foxes, and a hare-all new hosts for this tick species in Romania. Furthermore, we report for the first time occurrence of Ehrlichia sp. HF in I. apronophorus. Ehrlichia sp. HF was identified by sequencing a part of the 16S rDNA gene and was found in 16% (3/19) of the tested ticks. Ehrlichia sp. HF has not been previously reported in Eastern Europe and seems to have a much larger geographic distribution than previously known. Currently, it is unknown whether I. apronophorus is a competent vector for Ehrlichia sp. HF, or if the findings in this study represent infection in the hosts, namely dogs and fox.
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| 3. |
- Dwibedi, Chinmay Kumar, et al.
(författare)
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Long-range dispersal moved Francisella tularensis into Western Europe from the East
- 2016
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Ingår i: Microbial Genomics. - : Microbiology Society. - 2057-5858. ; 2:12
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Tidskriftsartikel (refereegranskat)abstract
- For many infections transmitting to humans from reservoirs in nature, disease dispersal patterns over space and time are largely unknown. Here, a reversed genomics approach helped us understand disease dispersal and yielded insight into evolution and biological properties of Francisella tularensis, the bacterium causing tularemia. We whole-genome sequenced 67 strains and characterized by single-nucleotide polymorphism assays 138 strains, collected from individuals infected 1947-2012 across Western Europe. We used the data for phylogenetic, population genetic and geographical network analyses. All strains (n= 205) belonged to a monophyletic population of recent ancestry not found outside Western Europe. Most strains (n= 195) throughout the study area were assigned to a star-like phylogenetic pattern indicating that colonization of Western Europe occurred via clonal expansion. In the East of the study area, strains were more diverse, consistent with a founder population spreading from east to west. The relationship of genetic and geographic distance within the F. tularensis population was complex and indicated multiple long-distance dispersal events. Mutation rate estimates based on year of isolation indicated null rates; in outbreak hotspots only, there was a rate of 0.4 mutations/genome/year. Patterns of nucleotide substitution showed marked AT mutational bias suggestive of genetic drift. These results demonstrate that tularemia has moved from east to west in Europe and that F. tularensis has a biology characterized by long-range geographical dispersal events and mostly slow, but variable, replication rates. The results indicate that mutation-driven evolution, a resting survival phase, genetic drift and long-distance geographical dispersal events have interacted to generate genetic diversity within this species.
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| 4. |
- Johansson, Anders, 1966-, et al.
(författare)
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Francisella tularensis : Tularemia
- 2012
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Ingår i: BSL3 and BSL4 agents. - Weinheim, Germany : Wiley-VCH Verlagsgesellschaft. - 9783527317158 - 9783527645114 ; , s. 71-84
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Bokkapitel (refereegranskat)abstract
- Francisella tularensis is the causative agent of tularemia. This emerging zoonosis shows several clinical manifestations complicating its diagnosis. The chapter focus on the characteristics of this bacterium, the several forms of the disease, its diagnosis and molecular epidemiology.
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| 5. |
- Johansson, Anders, 1966-, et al.
(författare)
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Francisella tularensis : Tularemia
- 2012
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Ingår i: BSL3 and BSL4 agents. - Weinheim, Germany : Wiley-VCH Verlagsgesellschaft. - 9783527317158 - 9783527645114 ; , s. 309-311
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Bokkapitel (refereegranskat)abstract
- This practical guide gives some starting points to manage biological safety issues with Francisella tularensis.
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